Obviously if the barn policy is that he must be turned out alone because he is shod, you can’t do anything about that (since you say he NEEDS the hind shoes), but I wonder if it’s not the turnout that he has a problem with, but the ALONE turnout.
I’m not saying there aren’t horses that don’t like turnout, because there are, but there is a difference between a horse being turned out with buddies … versus just being able to see buddies. Some really need that physical contact.